[Jean-Michel] tipped us off about his beer keg monitoring setup. It can tell you how much beer is left in each keg, how much carbon dioxide remains in the canister, and it can monitor and regulate temperature.
An Arduino mega is the brain of the system. A shield was built to interface force sensors, measuring the weight of the keg to estimate how much beer remains. Analog temperature sensors allow for temperature monitoring and control of the compressor for regulation. Information can be displayed on a graphic LCD or a computer via XBee wireless communications.
This is along the lines of the SparkFun kegerator but we like the added functionality. Does this need to Twitter? Probably not but if you want that, it’s only a bit of a software hack away.